Search results for "Moraine"

Does glacial environment produce glacial mineral grains? Pro- and supra-glacial Icelandic sediments in microtextural study

2022

Abstract Mineral grains from proglacial and supraglacial sedimentary settings in central south-eastern Iceland are considered in this study and analysed with the use of scanning electron microscope (SEM) techniques. By applying this, it is attempted to answer the key research question of whether quartz grains that come from a glacial-related sedimentary environment are indeed of glacial origin. The study also attempts to provide a linkage between microtextures produced on coarser and finer grains and to verify whether mineral grains from adjacent cryconite holes are similar or different. The preliminary assumption was that the more intense glacial grain record was based on several glacial a…

The Jura glaciers: palaeogeography in the Würmian circum-Alpine zone

2008

Since the first studies on the glacial formations of the Jura mountains there have been two concepts concerning type of glaciation and ice origin during the Wurmian glaciation. Some authors believed that the Jura was totally inundated by ice of Alpine origin, while others believed that the Jura had its own glaciers, originating from a single ice-cap. Several recent studies on both the NW and SE slopes of the range define the problem more accurately. This paper presents a synthesis of the new results from mapping the moraine systems and studying the stratigraphic relationships between Alpine and Jura tills. It is concluded that even the highest level of Alpine glaciers could not lead to a pe…

Investigating snowcover volumes and icings dynamics in the moraine of an Arctic catchment using UAV/ photogrammetry and LiDAR

2016

International audience; Means for assessing the contribution of the terminal moraine into the water budget of an Arctic glacier is investigated: on the one hand the terminal moraine represents a significant fraction (22%)of the catchment area of the glacier under investigation – Austre Lovenbreen, in the Brøgger peninsula, Spitsbergen – and on the other hand icings formation (or aufeis) each winter illustrates the contribution of subglacial water flow. While over the glacier, with a smooth surface readily interpolated, the winter and summer mass balances are assessed with only a few sparsely distributed stakes, such an approach is not valid with the rough topography of the glacier moraine: …

STOP 5: Veselava end moraine, north-western Vidzeme Upland

2014

Subglacial bedforms of the Zemgale Ice Lobe, south-eastern Baltic

2015

Abstract Presented in this paper are the results of the mapping of ∼6600 subglacial bedforms of the Zemgale Ice Lobe (ZIL), their composition and internal structure in the south-eastern Baltic region. Topographic maps at scale 1:10,000 were mainly used to map bedforms in Latvia, while a digital elevation model with cell size of 5 m was used for North Central Lithuania. The ZIL operated during the deglaciation of the Late Weichselian Scandinavian Ice Sheet (SIS), at least in the Middle Lithuanian and North Lithuanian glacial phases, and created a subglacial landform assemblage consisting of glacial lineations such as drumlins, mega-flutings, Mega Scale Glacial Lineations (MSGLs) and transver…

Fenoskandijas ledus vairoga Zemgales loba subglaciālās reljefa sistēmas un dinamika

2015

Pētījums ir veikts par Fenoskandijas ledus vairoga Zemgales loba subglaciālajām reljefa formām un ledāja dinamiku Viduslatvijas zemienē un Ziemeļlietuvas līdzenumos, akcentējot drumlinu, lielizmēra glaciālo lineamentu, rievoto morēnu un ledājūdeņu straumju lineāro veidojumu morfoloģiju, telpisko sakārtojumu, iekšējo uzbūvi un veidošanās apstākļu kopsakarību ar ledāja–gultnes mijiedarbības zonas termālo apstākļu laiktelpiskajām izmaiņām. Balstoties uz lielmēroga topogrāfisko karšu un augstas izšķirtspējas reljefa modeļu analīzi, kartētas subglaciālās reljefa formas un iegūti to morfometriskie parametri. Lauka pētījumos ir iegūti oriģināli, ģeotelpiski precīzi piesaistīti dati par subglaciālo…

STOP 15: Morphology and internal structure of a ribbed moraine and drumlin remnant in the environs of Baldone, Central Latvian Lowland

2014

Glacier drainage and sandur formation at Kötlujökull, South Iceland

1985

Abstract Over a number of years research on a stretch of the southeastern glacier margin of Kotlujokull in South Iceland, 8 km in length, has focused on correlating the manner of glacier drainage with the genesis of sandar, exemplified by the recent evolution of the glacier foreland. The research has yielded the following results. During an initial period, beginning prior to 1945 and ending between 1966 and 1975, a belt of moraines about 1 km wide was destroyed in stages, except for a few remnants, by 11 outbreaks of subglacial meltwater at different times and locations along the glacier front. These outbursts were associated with the genesis of “ordinary”; sandar, which are referred to her…

Antarctic erosion history reconstructed by Terre Adélie moraine geochronology

2020

AbstractWe report apatite fission-track and 10Be terrestrial cosmogenic nuclide (TCN) dating of 14 moraine boulders originating from inland Terre Adélie, East Antarctica. These data show cooling of the Proterozoic Terre Adélie craton at < ~120°C between 350 and 300 Ma, suggesting > 4 km temperate glacial erosion during the Late Palaeozoic Ice Age, followed by nearly null Mesozoic erosion and low glacial erosion (< 2 km) in the Cenozoic. Based on glacial flux maps, the origin of the boulders may be located ~400 km upstream. Preliminary TCN (10Be) datings of moraine boulders cluster within the last 30 ka. Cosmogenic ages from the Lacroix Nunatak suggest a main deglaciation after the …

Internal characteristics of ice-marginal sediments deduced from georadar profiling and sediment properties (Brøgger Peninsula, Svalbard)

2008

Abstract Georadar and sedimentological data were acquired in the Ny-Alesund area on Brogger Peninsula in order to study diamicton in frontal areas of Vestre Broggerbreen and Midre Lovenbreen. Parallel common offset georadar lines were acquired for information on thickness and layering and multioffset measurements served to deduce the subground velocity. Short permafrost cores (